Boiler



H. H. PEEK, SR 2,116,2H

BO`ILER Filed July 24, 1957 2 sheets-sheet 1 2 Z5 H. ,H. PEEK, SR

BOILER 2 Sheets-Sheet 2' Filed July 24, 1937 Patented May 3, 1938 UNlTED STATES PATENT OFFIQE BOILE-R Horace H. Peek, Sr., Chattanooga, Tenn.

Application July 24, 1937, Serial No. 155,437 a claims. (o1. 122-745 This invention relates to improvements in boilers and has special reference to improvements in the type of boiler shown in the Birchiield Patent No. 1,393,741 of which patent am now the owner.

The boiler disclosed in said patent has a firebox shell arranged within an outer shell and surrounded by water spaces, also the side sheets and the main crown sheet of the rire-box are preferably made from a single sheet bent to provide dependent side sheets and a downwardly curved crown sheet which is joined, at its side edges, to

the side sheets by reversely curved portions.

This patented boiler was developed and has been largely if not exclusively used for what is termed low-pressure heating.

However, the modern development has been in the direction of higher pressures, and the present invention relates especially to improvements in said type of boiler by which it can be safely used for producing the high pressures now being demanded both for heating and power purposes.

The peculiar form of boiler construction of said patented boiler has many important features which it is desired to retain in high-pressure boilers but when this form of boiler construction is subjected to the high pressures desired, weaknesses are developed which it is the special object of this invention to overcome.

It is one object of this present invention to provide stiiening, bracing or strengthening members for this type of boiler construction which shall permit this form of construction to be safely used for the high pressures desired.

It is a further object of the invention to provide an improved construction, in this regard, over that shown in U. S. Patent No. 2,079,503 of which I am now the owner, in that I arrange the stiftening, bracing or strengthening members Within the interiorgof the boiler where they are protected from direct Contact with the fire-box gases oi combustion.

It is obvious that the high internal forces to which the production of high pressures will subject the boiler would not only tend to spread the side walls of the outer shell but would also tend to depress the downwardly curved main crown sheet and draw the reversely curved portions inwardly from the side sheets of the outer shell, thus producing destructive or distorting actions which it is the object of this present invention to prevent or overcome.

Due to the location of the braces or stiffening or tension or distortion members at or near to the tops of the reversely curved portions of the re-box shell they are entireiy surrounded by the Water in the boiler, and thus protected from destructive changes in stresses and strains and due to their location the stresses which the braces H5 oppose are produced mainly by tension or distortion.

These stiffening members may be in the 4form of single units either welded or riveted to and upon the reversely curved portions of the hre-box 1'0 shell or they may also be joined or attached to the outer shell, thus connecting the inner and outer shells in a manner to prevent distortion thereof, or the stiffening members at opposite sides of the crown-sheet may be tied together by 'l5 tension plates, or in other forms oppositely disposed stiffening members may be connected together, and to the outer shell.

In other forms instead of single stiffening units they may be made in multiple form, that is, a number of stiffening members may be connected together, longitudinally of the boiler, and preferably also connected to the outer shell.

But whatever form of the invention is found best under any certain set of circumstances the 25 fundamental idea is preserved of applying varied forms or shapes of stiifening, bracing or strengthening members to the reversely curved side edge portions of the fire-box shell and which members are arranged Within the interior of the boiler and 30 thus protected from the gases of combustion.

Other features of advantage and benefit will become apparent from the following description taken in conjunction with the appended claims and the accompanying drawings forming part of I35 this specification. It should be understood however that such drawings and description are typical merely of my invention and that my invention is not to be limited in anywise thereby.

In said drawingsz- Fig. l is a vertical, central, longitudinal section on the line i-l of Fig. 2 of a boiler of the type mentioned and showing a simple form of the invention; 4

Fig. 2 is a fragmentary, vertical, transverse sec- 45 tion taken on the line 2--E of Fig. 1 and showing the form of the invention portrayed in Fig. l;

Fig. 2a. is similar to Fig. 2, but shows a slightly modified form of the invention;

Fig. 3 is a section similar to Fig. 2, and showin 50 still another form oi the invention;

Fig. 4 is a fragmentary, horizontal section on the line 4-4 of Figs. l. and 2;

Fig. 5 is a section similar to Fig. l but taken on the line 5 5 of Fig. 2a; 55

. `flue sheet 38.

Fig. 6 is a fragmentary, horizontal section simi- Ylar to Fig. 5 but showing a riveted instead of a welded construction;

Fig. 7 is a fragmentary, vertical section similar to Fig. 2a, but taken on the line 1 7 of Fig. 6;

Fig. 8 is a fragmentary, horizontal section on the line 8--8 of Fig. 3;

Fig. 9 is a fragmentary, horizontal section similar to Fig. 4 but showing another modification of the invention;

Fig. 10 is a fragmentary, vertical, transverse section on the line IIJ- l of Fig. 9;

Fig. 11 is a fragmentary, vertical section similar to Fig. 4 but showing another slightly modified form of the invention; and

Fig. 12 is a fragmentary, vertical section on the line |2-|2 of Fig. 11.

The boiler shown in the drawings has an outer shell I of inverted U-shape and within this shell is arranged an lvl-shaped fire box i6 separated from the outer shell by side water legs l1, a front water leg I8 and a rear water leg i3.

Preferably as shown, the fire-box i6 is made up mainly of a single sheet of sheet metal formed to provide downwardly extending side sheet portions 2, a downwardly curved crown sheet portion 2| which is connected at its side edges with the side sheet portions by upwardly or reversely curved portions 22, of relatively small radius.

The lower edges of the outer boiler shell and the lire-box shell are co-incident and the lower ends of the water legs which are provided be tween these two shells are closed by a bottom ring 23. This ring 23 nts between the inner and outer boiler shells and is preferably welded at its inner and outer edges to the inner and outer shells as shown at 24.

The downwardly curved crown sheet portion rounds out the body of the boiler which is mainly formed by the outer sheet I5 and provides capacity for more fire flues than if it were curved upwardly.

As usual the outer and inner sheets of the boiler are connected by suitable stay bolts 25.

In the form of boiler shown, the fire-box has a main combustion chamber 26 below the crown sheet 2| and an auxiliary combustion chamber at the rear end of the boiler which rises above the main crown sheet as shown at 21.

As usual the fire-box is closed at its front end by a vertical sheet 28 and at its rear end by a vertical sheet 29 which preferably is formed at its upper end to close the top of the auxiliary combustion space. The forward end of the auxiliary combustion space is closed by a vertical The outer shell is completed by a vertical sheet 3| at the front end of the boiler and a vertical sheet 32 at the rear end of the boiler.

Horizontal fire flues 33 lead forward from the auxiliary ue sheet 30 to the front boiler sheet 3| and a second set of horizontal nre nues 34 above the flues 33 lead rearwardly from the front boiler sheet 3| to the rear boiler sheet 32.

It should be understood that, to complete the boiler for use, a smoke box is added at the front of the boiler to guide the flue .gases from the lower set of flues to the upper set of flues and that a suitable smoke pipe is provided to connect the rear end of the boiler to a suitable stack for carrying away the flue gases.

It is a special object of this present invention to so strengthen and stiifen the upper part of the lire-box including the downwardly curved crown sheet 2| and the reversely curved portions 22 at the lateral edges of the crown sheet that this construction of boiler can be safely used for the high pressures desired.

For this purpose I provide stiffening and strengthening members which embrace the reversely curved portions 22 and are rigidly secured thereto and which lie wholly within the interior of the boiler within the water space thereof.

The most simple form of such stiffening members is shown in Figs. 1, 2 and 4 at 35, and consists of a Vertical central plate 36 arranged to span one of the portions 22.l 'I'his plate 36, as shown, is arranged transversely of the boiler and its lower edge is out out, as shown at 31, to t on the reversely curved portion 22.

Preferably the plate 36 is made more rigid by applying metal angle pieces 38 thereto, as shown, two angle pieces on each side and the adjacent legs of these angle members are rigidly connected together. The stiffening unit thus formed may be secured to, and on the reversely curved portion 22 by welding as shown by the heavy line 39 or the lower edges of the plates 36 may be bent to form a flange 40 for contact with the reversely curved portion 22 and the unit connected to the reversely curved portion by rivets as indicated in Fig. 6.

It is usual to provide a plurality of these stiffening units 35 at each side of the boiler, four such units being shown in Fig. l, spaced along the reversely curved portion 22.

While this simple form of stiifening unit is effective for pressures higher than those ordinarily used in low pressure heating, I have found that it is best, for some pressures, to connect the units 35 to the outer shell preferably by extending the central plate 36 to meet the outer shell as shown in Figs. 2ay and 5 at 4| and securing it to the outer shell preferably by welding as shown at 42, although in some instances its outer edge portion may be bent 01T at a right angle as shown at 43 Figs. 6 and 7 and the unit connected to the outer shell by rivets as shown.

Under still other conditions, such as extremely high pressures, I have found that it is best to cross connect the units arranged at the opposite sides of the boiler. Preferably I accomplish this by providing transversely extending plates 44, Fig. 3, which are preferably though not necessarily continuations of the central plates 3E. These transverse plates, which may be termed tension plates, are provided with suitable openings 45 to permit the installation of the lower re ues 33.

Obviously, when the tension plates 44 are used, they may be extended through the stiffening units to the outer shell and their transverse ends connected to the outer shell preferably by welding as indicated at 46, or their outer ends may be bent at right angles to form a flange 41 adapted to be secured to the outer shell by rivets as indi- 'cated in Fig. 8.

vention this multiple unit may be connected to the outer shell of the boiler. When this is desired, I preferably extend the ends of the outer longitudinal plate 50 as shown at 53 and form them into contact with the outer shell and obviously they can be rigidly connected to the outer shell by rivets as shown or by welding.

In Figs. 11 and 12 I have shown a very simple form of stiffener.

This form as shown at 54 is made up of a piece of I-shaped structural steel which is formed to t upon the reversely curved portion 22 and preferably the member is of such a size that its outer end 55 fits snugly between the outer and inner shells of the boiler as shown in Fig. 11.

The form of this unit, being provided with inner flanges 56 and outer flanges 51 lends itself fil tions, and means permanently connecting the outer ends of said plates to the proximate side wall of the outer shell as and for the purpose specified.

2. The invention as dened in claim 1, and a transverse tension plate connecting oppositely arranged stiffenn-g plates.

3. In a boiler having a re-box shell within an outer shell and separated therefrom by Water spaces, the hre-box shell having depending side sheets and a downwardly curved crown sheet joined at its lateral edges to the side sheets by reversely curved portions, tension members extending across the boiler, within the water space thereof and permanently secured to the outer shell of the boiler and to said reversely curved connecting portions of the fire-box shell.

HORACE H. PEEK, SR. 

